JP2003526768A - Handheld sensing device - Google Patents

Abstract

(57) [Summary] A vapor sensing device that is sufficiently small and lightweight for handling, and that can be conveniently adapted to detect the presence and concentration of a wide range of specified steam. The device provides these advantages using a sensor module that incorporates a plurality of sensors on a chip that is releasably held in or adjacent to the sample chamber and the sample chamber. Optionally, the sensor module can be configured to releasably insert into a socket formed in the device. The vapor is directed through the sample chamber, where the sensors emit different combinations of their corresponding electrical signals. The sensors of the sensor module may take the form of a chemical sensing resistor having a resistance that varies according to the identity and concentration of adjacent vapors. These chemical sensing registers can be connected in series with the reference register between the respective reference voltage and ground so that an analog signal is established for each chemical sensing register. The resulting analog signal is provided to an analog to digital converter to generate a corresponding digital signal. These digital signals are appropriately analyzed for vapor identification.

Description

Detailed Description of the Invention

CROSS REFERENCE TO RELATED APPLICATIONS This application describes US patent application Ser. No. 09 / 045,2, filed Mar. 20, 1998.
No. 0, filed October 23, 1998, which is a continuation of 37
This is a partial continuation of 9 / 178,443. This application is also a continuation in part of US patent application Ser. No. 09 / 141,847 filed August 27, 1998. The present application further claims the benefit of US Provisional Application No. “Electronic Nose Device” filed March 3,1999. The entirety of these applications are referenced as an integral part of this application. BACKGROUND OF THE INVENTION The present invention relates to analyte detection and identification using portable sensing devices. More particularly, this invention relates to portable handheld electronic nose devices.

Electronic noses are instruments used for the detection of chemical analytes in vapors or gases, solutions and solids. In some cases, electronic noses are used to simulate the mammalian olfactory system. Generally, an electronic nose is a system with a sensor array for use with pattern recognition algorithms. A recognition algorithm identifies and / or quantifies the analyte of interest using a combination of chemical sensors that produce a unique pattern of vapor or gas or fingerprints. Therefore, the electronic nose can recognize unknown chemical analytes, odors and vapors.

In practice, the electronic nose is given a substance such as odor or vapor, and the sensor converts the input of the substance into a response such as an electrical response. This response is then compared to the previously saved known response. The unknown analyte can be determined by comparing the chemical signature of the unknown substance with the “signature” of the known substance. Different sensors can be used on the electronic nose to respond to different classes of gases and odors.

Electronic noses include environmental toxicology and remediation, biomedical such as microbial classification or detection, material quality control, food and agricultural product monitors, heavy industry manufacturing, atmospheric monitoring, worker protection, emission control, product quality testing. It can be used for a wide range of commercial purposes including, without limitation.
Many of these applications require portable devices because they are in-situ or inaccessible to large experimental desktop models. Traditionally, most electronic noses have been large, bulky experimental models that cannot be used in the field or in pilot plants. If available, portable or handheld devices will provide the required portability to pilot plants and sites. Unfortunately, the portable chemical detectors developed to date have many limitations that prevent wide acceptance.

For example, US Pat. No. 5,356,594 issued to Neel et al. Discloses a portable volatile organic monitoring system designed for fugitive emissions detection. The device includes a bar code reader that outlines the discharge location. The device includes one sensor responsive to ionized gas, but the device only detects the amount (ie concentration) of volatile compounds. This device cannot identify volatile organic compounds. As such, this device is a vapor volume recorder, not a portable electronic nose. Therefore, the user must know the identity of the vapor to be quantified,
Or this information must be stored elsewhere.

Another example of a portable device is US Pat. No. 4, issued to Stetter.
No. 818,348. This portable device is more advanced than the previous example,
After all, there are many limitations. In this case, the device can identify gases or vapors, but its application is quite limited due to the structural limitations of the sensor. Since the sensors that make up the array are permanently fixed, the device can identify very few analytes and gases. Moreover, the reproducibility and stability of the device is very limited because the analytes or vapors that identify interfere with each sensor of the array in different amounts. Such limits affect the accuracy of the device in identifying unknown substances.

In view of the foregoing, there remains a need in the art for a portable and sometimes hand-held electronic nose. In addition, there is a need for a device that is versatile and can accurately accommodate a wide range of gases, analytes and fluids. What is needed is a vapor sensing device that is highly versatile, stable, and meets the needs of a wide range of industries and users. The present invention meets these and other needs.

SUMMARY OF THE INVENTION The present invention relates generally to sensing devices (also referred to as electronic nose or e-nose devices). The device is compact and, in some embodiments, configured as a handheld device. The e-nose device can be used to measure, identify (detect and / or classify) or quantify one or more analytes in a vapor, liquid, gas, solid or other medium. This e-nose device embodiment includes at least two sensors (
Ie, an array of sensors), and in other embodiments from about 2 to about 200 in the array.
There are 4 sensors, preferably about 4 to about 50 sensors in the array.

This e-nose device is versatile and meets the needs of a wide range of applications in various industries.
In one embodiment, the device is designed as a slim handheld portable device with various features. In another embodiment, the device is designed as a full-featured portable field tool. The e-nose device typically includes an internal processor for processing the sample and reporting the data. Optionally, the device can be connected to a computer, such as a personal computer, to access setup and advanced features and to transfer data files.

In one embodiment, portions of the e-nose device are located in modules that can be mounted, swapped, and replaced as needed. For example, sensor modules, sampling rods or noses, battery packs, filters, electronics, and other components can be modularized as described below. This modular design increases usability, enhances performance, lowers cost, and adds flexibility and other advantages not found in conventional e-nose devices.

One embodiment of the present invention provides a handheld sensing device that includes a housing, a sensor module, a sample chamber and an analyzer. The sensor module and analyzer are mounted in the housing. The sensor module includes at least two sensors that provide different characteristics or signature responses that can be used to measure, identify (such as detect and / or classify), or quantify the analytes present in the test sample. The sample chamber is defined by the housing, the sensor module, or both, and incorporates an inlet port and an outlet port. The sensor is located in or adjacent to the sample chamber. The analyzer is configured to analyze a particular response from the sensor and identify or quantify the analyte in the test sample based on the particular response. In a variation of the above embodiment, the housing of the handheld sensing device includes a socket,
The sensor module is removably mounted in the socket of the housing. In this example, the sensor module may include one or more sensors.

Another embodiment of the invention provides a sensor module configured for use with a sensing device. The sensor module is located within the housing that defines the socket. The sensor module includes a casing, a sample chamber, an inlet port, an outlet port, at least two sensors, and an electrical connector. The casing is sized to be received in the socket of the sensing device. The inlet port is configured to be releasably engageable with the port connection of the sensing device when the sensor module is received in the socket. The inlet port receives the test sample from the sensing device and directs the test sample into the sample chamber. The outlet port is configured to discharge the test sample from the sample chamber. The sensor is located at or adjacent to the sample chamber and is configured to give different responses when exposed to one or more analytes within the sample chamber. The electrical connector is configured to be releasably engageable with the mating electrical connector of the sensing device when the sensor module is received in the socket. The electrical connector sends a characteristic signal from the sensor to the sensing device.

Yet another embodiment of the present invention provides a handheld sensing device for measuring the concentration of one or more analytes in a sample chamber. The sensing device includes two or more chemical sensing resistors, a conditioning circuit, an analog to digital converter (ADC), and an analyzer. Each chemical sensing resistor has a resistance that varies depending on the concentration of one or more analytes in the sample chamber. The conditioning circuit interfaces with the chemical sensing resistor and produces an analog signal indicative of the resistance of the resistor. The ADC is connected to the adjusting circuit and outputs a digital signal corresponding to the analog signal. The analyzer is coupled to the ADC and determines the identification or concentration of the analyte in the sample chamber based on the digital signal.

Yet another embodiment of the present invention is a portable handheld vapor sensing device that includes a sensor module that incorporates a plug-in array of vapor sensors that each provide an electrical response to one or more different vapors. I will provide a. The device includes a handheld housing, and the sensor module can optionally be removably attached to a socket formed within the housing. The sensor module defines a sample chamber exposing the vapor sensor array. The sample chamber incorporates a vapor inlet and a vapor outlet and a pump is mounted within the housing for directing a vapor sample from the vapor inlet through the sample chamber to the vapor outlet. A monitoring device is also mounted within the housing and monitors the electrical response of the array of vapor sensors and produces a corresponding plurality of sensor signals. In addition, an analyzer is mounted within the housing to analyze the sensor signals and identify the vapor sample that is pumped through the sample chamber.

In a more detailed feature of the present invention, the handheld vapor sensing device further comprises a controller or processor configured to control a pump for passing one of the plurality of reference vapors or an unknown vapor sample into the sample chamber. Including. A monitoring device monitors the electrical response of the array of vapor sensors to produce a reference signature when the controller controls the pump to pass one of the plurality of reference vapors into the sample chamber. The monitor then monitors the electrical response of the array of vapor sensors to generate a vapor sample signature as the controller controls the pump to pass the unknown vapor sample through the sample chamber. The analyzer then compares the vapor sample signature with multiple reference signatures to identify an unknown vapor sample.

In another more detailed feature of the invention, the sample chamber of the handheld vapor sensing device is defined by the sensor module only and is sealed from the external environment except the vapor inlet and vapor outlet. Further, each sensor module includes a plurality of first electrical connectors and a plurality of generally identically sized and shaped devices, both of which hold an array of vapor sensors, each having a second electrical connector on one edge. Including 1 of 1st electrical connector
Engage with one.

In yet another detailed feature of the invention, the handheld vapor sensing device further comprises:
It includes electrical circuitry that controls the temperature of the vapor sensor array. Further, when the sensor module is removably mounted in the housing socket, the module has an identifier for identifying the vapor sensor therein and the monitor is configured to read the identifier held by the sensor module received in the socket. .

In one embodiment, the sensor is implemented by a chemical sensing resistor having a resistance that varies in response to one or more predetermined vapor concentrations in the sample chamber. These chemical sensing resistors are connected in series with the reference resistors between the respective reference voltage and ground so that an analog signal is established for each chemical sensing resistor. The analog-to-digital converter responds to these analog signals and the reference voltage and produces a digital output signal indicative of the resistance of the various chemical sensing resistors. A multiplexer can be included to serially connect various analog output signals to an analog-to-digital converter.
Further, the analyzer is responsive to the digital output signal to determine the presence and / or concentration of one or more predetermined vapors within the sample chamber.

Other features and advantages of the invention will become apparent from the following description of the embodiments, which is read in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

Description of Specific Embodiments FIG. 1 shows a pictorial view of an operator using the e-nose device 100 of the present invention. Figure 1
In the illustrated embodiment, the e-nose device 100 is a portable, hand-held tool for detecting the presence of one or more designated analytes in a particular sample. As used herein, a sample is a vapor, liquid, solution, gas, solid or other form of unit of the entity to be analyzed and mixtures thereof. The sample thus contains chemical analytes, odors, vapors and others. The sample can consist of a single analyte or multiple analytes. In FIG. 1, the e-nose device 10
0 is used for industrial monitoring and detection, i.e. for identifying and quantifying harmful gases leaking from industrial valve assemblies. The e-nose device 100 can also be used for many other applications, as listed below.

FIG. 2A shows a top perspective view of an example of an e-nose device 100a. The e-nose device 100a includes a rod-shaped housing 110a having a rear end sized to be conveniently grasped and supported by an operator's hand. A display 120a and a number of pushbutton control switches 122a-on the top surface of the housing for convenient access and viewing by an operator.
122c is arranged. The display 120a displays the operation mode and the detection result of the device.

A tubular sampling rod 130a and a drain port 134 are provided for receiving and draining each sample to be analyzed. The sampling rod is also called the nose or nose. The plug-in sensor module 150a is shown mounted in a socket located at the base of the e-nose device 100a. The operation of sensor module 150a is described in detail below. Housing 1
An electrical connector 126 located at the rear end of 10a enables communication with the host computer and electrical contacts 128 are used to operate the e-nose device and charge the rechargeable battery within the e-nose device. Allows the application of power.

FIG. 2B shows a bottom perspective view of the e-nose device 100a. As shown in FIG. 2B, one sampling rod 130a1 is placed in a safe place and a second sampling rod 130a2 is housed in a rod-shaped recess 162 located on the bottom of the device 100a. The sampling bar 130a can be stored when not in use and is releasably placed in a safe location by a pair of spring clips 164a and 164b. Plug-in sensor module 150a is shown removed from its socket 152.

FIG. 3A shows six perspective views of another e-nose device 100b embodiment. The e-nose device 100b includes a nose 130b, a display 120b and a set of buttons 124. As with the e-nose device 100a, the nose 130b in the e-nose device 100b is removably attached to the housing 11b. A set of connectors 127 allows interconnection with external devices and systems. FIG. 3B shows four different embodiments of noses 130c-130f. As these examples show, the nose can have spatial dimensions to improve performance in particular applications.

FIG. 4 shows a diagram of an embodiment of a subsystem of the e-nose device 100. The upper half of FIG. 4 shows the electrical subsystem 410 and the lower half shows the subsystem 412 that processes (ie, substantially mechanical) the test sample. A test sample is received within subsystem 412 via nose 430 and provided to manifold 440. Similarly, a reference or background sample is received via the intake port 432.
It is provided to manifold 440 via filter 436. The filter 436 is
It may be a blank filter, carbon filter or others. Manifold 4
40 directs the test and standard samples to solenoid 444 which selects one sample as the solenoid output. The selected sample is directed to sensor module 450 through manifold 440. The sensor module 450 includes at least two sensors that detect the analyte in the selected sample. Sensor module 4
50 produces a signal (or "signature") representative of the detected analyte and provides this signal to electrical subsystem 410. Selected samples are then manifold 440
Through sensor module 450 and through pump 460 to exhaust port 434. The nose 430, intake port 432, exhaust port 434, and sensor module 450 of FIG. 4 are each generally the nose 1 of FIG. 2A.
30a, intake port 132, discharge port 134 and sensor module 15
Corresponds to 0a.

FIG. 4 illustrates an embodiment of subsystem 412. Many other components and devices (not shown) can be included in subsystem 412. Moreover, not all of the components and devices shown in Figure 4 need be present to practice the invention. In addition, the components and devices may be arranged differently than that shown in FIG. For example, pump 460
Can be coupled to the output of solenoid 444 instead of exhaust port 434.

As shown by the embodiment of FIG. 4, the electrical subsystem 410 includes a display 472, a battery pack 474, a keypad 476, an analog port 47.
8. Includes PCB assembly 470 interconnecting interface 480 and switches 482a and 482b. Display 472 may be a liquid crystal display (LCD) and may include a backlight controller driver and (optionally) a touchpad. A contrast adjustment mechanism may be provided to adjust the display 472. Electrical subsystem 4
10 will be described in more detail below.

FIG. 5 shows an exploded perspective view of some of the major components of the e-nose device 100a. FIG. 5 similarly depicts an example of subsystem 412a. When using e
The nose device 100a is mounted to inhale from a location of interest (ie, the space adjacent to the valve assembly of FIG. 1) through the sampling rod 130a into the test sample (ie, into the vapor, liquid or gas medium) and to the socket 152. The sample is arranged so as to be guided through the plug-in sensor module 150a.
After passing through the sensor module 150a via ports 512a and 512b, the sample is directed to the outside through an outlet port 134 on the side of the device. During various operating modes of the device, a standard number of times a standard sample is drawn into the device via the intake port 132, guided through the sensor module 150a, and exhaust port 13.
It is discharged through 4.

The device housing 110a may be formed of molded plastic, and the upper half 11
2a and lower half 112b are included. The internal components of many devices are conveniently and efficiently mounted on a printed circuit board (PCB) 510 that extends substantially across the interior space of the device. The display 120a is mounted on the top of the PCB and is visible through the gap 520 formed in the upper half 112a of the housing. The push button control switches 122a-122c are mounted on the underside of the display 120a and in positions where they can extend through correspondingly sized openings 522 formed in the upper half 112a of the housing.

A valve assembly 540 mounted on the underside of the PCB 510 receives the test sample drawn into the e-nose device 100a via the sampling rod 130a and the standard sample via the intake port 132. The test sample is directed from sampling rod 130a to the valve assembly via tube 532 and the clean sample is directed from intake port 132 to the valve assembly via tube 534. The valve assembly 540 is arranged to select the two incoming sources via either the sampling rod 130a or the intake port 132. The sample from the selected source is directed from the valve assembly 540 through the tube 152 to the sensor module 150a through the socket 152 located on the top surface of the PCB. After analysis by the sensor module, the sample is led through tube 538 to a pump 560 located under the PCB. Finally, the sample is exhausted from the device by being guided from pump 560 to exhaust port 134 through tube 562. Alternatively, pump 560 can be located in the passageway between valve assembly 540 and sensor module 150a. In some embodiments, the components (including tubes 532, 534, 536, 538 and 562) that come into contact with the sample to be processed include:
It is formed of an inert or non-corrosive material such as Teflon ™, stainless steel or Teflon ™ coated metal. The valve assembly 540 of FIG. 5A generally corresponds to the manifold 440 and solenoid 444 of FIG.
The pump 560 corresponds to the pump 460.

In one aspect, the handheld device of the present invention includes an optional preconcentrator (
A preconcentrator) is included. For certain analytes, such as high vapor pressure analytes, it is desirable that the analyte be concentrated with an absorbent. The preconcentrator can be used to increase the concentration of analyte in the test sample. The preconcentrator is a trap made of absorbent material. In use, the absorbent material attracts molecules from a gaseous sample that is concentrated at the surface of the absorbent. The sample is then "released" and analyzed. Included are polymeric absorbent materials, non-silanized glass wool, Teflon ™ or porous glass fibers, and any other suitable pre-concentrated material. The absorbent material is filled into a tube, such as a steel tube.

In use, the sample is aspirated into a trap that concentrates the component of interest. In some cases, the tube is covered with a wire through which the flow in the tube can be heated to release the test sample. The sample is then transferred into the module containing the sensor.

The preconcentrator can be placed at various positions between the sampling rod and the sensor module. In one aspect, the preconcentrator can be located at a convenient location upstream of the nozzle of the device, or alternatively a manifold or other sensor module. For example, the preconcentrator may be located within the valve assembly 540 or contained within a unit associated with the valve assembly (not shown in FIG. 5). As an option
Additional valves can be incorporated into the device with preconcentration and detection.

Suitable commercially available absorbent materials for use in the preconcentrator include Tenax TA ™, Tenax GR ™, Carbotrap ™.
, Carbo Packs B and C, Carbo Trap C (trademark), Carboxen (trademark),
Carbosieve SIII ™, Polapack ™, Sherocurve ™ and combinations thereof, but are not limited thereto. Preferred combinations of absorbent materials include Tenax GR and Carbo Pack B, Carbo Pack B and Carbo Sheave SIII, and Carbo Pack C and Carbo Pack B and Carbo Sheave SIII.
Alternatively, there is a carboxen 1000, but the present invention is not limited to this. Those skilled in the art
You will be aware of other suitable absorbents.

The operation of the e-nose device 100 is controlled by a processor located in an electrical unit 570 mounted on the top side of the PCB 510. Electric unit 570
Further includes one or more memory devices for storing program code, data and other placement information. The control of the electronic unit and the e-nose device is described in more detail below.

FIG. 6A shows an exploded perspective view of another embodiment of subsystem 412b. Subsystem 412b includes manifold 640a attached to manifold seal plate 642a. Manifold 640a includes a fitting for mounting valve (or solenoid) 644a, a fitting for mounting sensor module 650a, and a fitting for mounting pump 660a.
The sample is passed through a manifold 640a and a cavity located in a tube (not shown) to various subassemblies (eg, valve 644a, sensor module 6).
Guided between 50a and pump 660a). The manifold 640a also has
It includes a recessed opening 648a arranged to receive the filter 636a.

FIG. 6B illustrates an exploded perspective view of yet another subsystem 412c embodiment. Subsystem 412c includes manifold 640b attached to manifold seal plate 642b via seal plate gasket 644b.
Manifold 640b includes a fitting for mounting valve (or solenoid) 644b and a fitting for mounting pump 660b. The filter cartridge 646b includes a recessed opening 648b that is mounted on the top surface of the manifold 640b and is arranged to receive a filter element. The filter cover 636b provides a recessed opening 64 that provides a filter seal.
8b and O-ring 638b. The sample is passed through the manifold 640b and a cavity located in a tube (not shown) to the various subassemblies (
For example, it is guided between the valve 644b and the pump 660b).

Filter 636, manifold 640, valve 644, sensor module 650 and pump 660 of FIGS. 6A and 6B are equivalent to filter 436, manifold 440, solenoid 444, sensor module 450 and pump 46 of FIG. 4, respectively.
Corresponds to 0.

FIG. 6C shows an exploded perspective view of an embodiment of the filter. The filter includes a circular base unit 680 having an outer wall 682 and an inner wall 686. A set of small size openings are located inside the outer wall 682 to draw sample into the filter. An inner circular ring 684 covers an inner wall 686 having another set of smaller size openings disposed therein for drawing sample from the filter. A filter material (eg charcoal) 688 for filtering the sample is located in the space between the outer and inner walls. The O-ring 638b is used to seal the filter.

7A-7B are mounted in two sample chambers 710a and 710b,
FIG. 3 shows a perspective view and a top cross-sectional view, respectively, of an embodiment of a sensor module 150b including four sensor devices. 7A and 7B, the sensor module 150b is depicted as being permanently attached to the PC, but may instead be configured as a plug-in module, such as the sensor module 150a. it can. In a particular embodiment, the sensor module 150b includes four plug-in sensor array devices 720, each of which includes eight chemical sensitive sensors 740.
Is a combination of. Sensor module 150b may include a greater or lesser number of sensor array devices, and each sensor array device may include a greater or lesser number of sensors. Four sensor array devices 72
The zeros are mounted vertically in pairs on board 730. The board 7 has a pair of rod-shaped recesses 732 defining two separate sample chambers 710a and 710b, one for each pair of sensor array devices 720.
It is fixed at 30. The sensor array device 720 is similar in shape and size, with four connectors or receptacles 722 each formed on the board 730.
Can accept any one of

FIG. 7C shows a perspective view of the sensor array device 720. In an example, each sensor array device 720 includes an array of eight chemically sensitive sensors 740, each of which exhibits a particular qualitative response when exposed to a test sample bearing an analyte to be detected. I'm out. In one embodiment, the sensor is implemented with a chemical sensing resistor that exhibits a specific resistance when exposed to the test sample. An electrical connector 742 having multiple contacts is disposed along the lower edge of the sensor array device 720,
It is arranged for insertion into one of the four receptacles 722. A suitable sensor array of this type is known from US Pat.
No. 575,401. This patent specification is referenced as an integral part of this application. Those skilled in the art will appreciate that various alternative chemical sensitive sensors or devices can be used as well.

As shown in FIG. 7B, the test sample is transferred from the intake port 750 through the two sample chambers 710 a and 710 b to the exhaust port 760 and to the sensor module 15.
Guided through 0b. The sensor array device 720 is arranged such that the test sample moves horizontally across the exposed chemically sensitive sensor. Baffle 762
And 764 are located at the respective leading and trailing ends of each sample chamber to help provide an efficient flow pattern, as shown in FIG. 7B.

FIGS. 8A and 8B show perspective and top cross-sectional views, respectively, of another sensor module 150 c embodiment that includes four plug-in sensor devices 820 within one cavity or sample chamber 810. The sample chamber 810 is partially defined by a cover 832 that is disposed over the board 830. This arrangement is designed to provide the test sample with a longer residence time in the sample chamber, which is advantageous in some applications.

Similar to the chemically sensitive sensors included in the sensor array device 720 of FIGS. 7A and 7B, the chemically sensitive sensors included in the sensor array device 820 of FIGS. 8A and 8B are described in US Pat. No. 5,575,401. It may take the form of the array disclosed in. Those skilled in the art will appreciate that various alternative chemical sensitive sensors or devices may be used as well.

9A and 9B show perspective and side cross-sectional views, respectively, of yet another sensor module 150 d embodiment that includes one sensor array device 920. In a particular embodiment, sensor array device 920 includes 32 chemically sensitive sensors arranged in a two-dimensional grid and mounted generally horizontally on sockets 922. Of course, the sensor array device 920 can include more or less sensors. Screen 924 (see FIGS. 9B and 9C) covers sensor array device 920, and in some embodiments includes a separate aperture 926 that covers each chemical sensing sensor. The screen 924 is attached to the cover 932.
The combination defines an upper chamber 934 and a lower chamber 936. As shown in FIG. 9B, the test sample being analyzed is transferred from the intake port 950 to the upper chamber 934.
From there, it is directed through screen 924 to lower chamber 936, where it passes across the chemical sensing resistor. The test sample then exits through the exhaust port 960. Again, it will be appreciated that various alternative chemical sensitive sensors and devices could be used as well.

The e-nose device of the present invention includes an array of sensors, in some cases US Pat.
The sensor described in No. 571,401 is used. Various sensors suitable for detecting analytes include surface acoustic wave (SAW) sensors, quartz microbalance sensors, conducting composites, chemical resistors, metal oxide gas sensors such as tin oxide gas sensors, organic gas sensors, metals. Oxide field effect transistor (MOSFET)
, Piezo electric devices, infrared sensors, sintered metal oxide sensors, Pd-gate MOS
FETs, metal FET structures, metal oxide sensors such as Tuchuchi gas sensors, phthalocyanine sensors, electrochemical cells, conductive polymer sensors, catalytic gas sensors, organic semiconductor gas sensors, solid electrolyte gas sensors, piezo electric quartz crystal sensors and Langmuir-Blodgett film sensors Including, but not limited to.

In a preferred embodiment, the sensor of the present invention is disclosed in US Pat. No. 5,571,401. This patent specification is referenced as an integral part of this application. Briefly, the sensor described therein is a conducting material and a non-conducting material arranged in a matrix of conducting and non-conducting areas. The non-conductive material may be a non-conductive polymer such as polystyrene. The conductive material can be a conductive polymer, carbon black, an inorganic conductor and the like. The sensor array consists of at least two sensors, typically about 32 sensors and in some cases 1000 sensors. An array of sensors can be formed on an integrated circuit using semiconductor engineering methods, one example of which is the PCT published on February 19, 1999, entitled "Methods and Systems for Analyte Detection". It is disclosed in patent application WO 99/08105. This application is referenced as an integral part of this application.

In some cases, the handheld device of the present invention comprises a surface acoustic wave (SAW) sensor, preferably a polymer-coated SAW sensor. SAW devices include up to six, typically four sensors in an array. The device optionally includes a preconcentrator with a heater for sample dissociation.

As will be appreciated by those skilled in the art, the sensors that make up the array of the present invention can be constructed from the various sensor types described above. For example, the sensor array can consist of conductive / non-conductive area sensors, SAW sensors, metal oxide gas sensors, conductive polymer sensors, Langmuir-Blodgett film sensors and combinations thereof.

FIG. 10 shows various accessories for an e-nose device. A container 1010 is provided for easy transportation of the e-nose device and its accessories. Electric cord 1
012 and automotive cord 1014 may interconnect each of the power sources (ie, wall sockets or car lighters) and the e-nose device to charge the rechargeable battery in the e-nose device. These codes also allow operation of the e-nose device without batteries. The bracket or stand 1016 holds the e-nose device in the required position. The battery 1018 (main or spare) allows the e-nose device to be used without connection to a power source. Serial cable 1020 and analog cable 1022 are used to interconnect the e-nose device with personal computers and other test devices. A touch pen 1024 is prepared for use with the touch screen. One or more noses 1030 can be similarly prepared as spares or for use in a particular set of applications. A sample syringe 1032 can be used for collection of test samples.

FIG. 11 is a perspective view of the e-nose device shown mounted vertically on the charging station 1108 and connected to the host computer 1110. The charging station 1108 connects the rechargeable battery of the e-nose device 100 to the electrical contacts 128 (FIG. 2).
(See A and 2B). The e-nose device 100 is also depicted as being coupled to the host computer 1110 via data line 1120. The host computer 1110 collects information from the device, such as the results of a sample analysis of the device, as well as various information such as the identification of the various target vapors to which the device is exposed to the e-nose device 100. Can be used to update.

FIG. 12A is a diagram of an example of an electrical circuit within an e-nose device. In one embodiment, an electrical circuit measures the resistance of an array of chemically sensitive resistors mounted on a sensor array device (see FIGS. 7-9) and processes these measurements to identify and quantify the test sample. To do. The circuit is partially mounted on the PCB, the processor 1210,
It includes a volatile memory (referred to as RAM) 1212, a non-volatile memory (referred to as ROM) 1214, and a clock circuit 1216. A plug-in sensor module 150a is used (see FIGS. 2A and 5). In this embodiment, the chemical sensing resistor is a mating electrical connector 552a that engages when the sensor module 150a is plugged into the e-nose device 100a. And 552b (see FIG. 5) to the electrical circuit.

The chemical sensing resistor used to implement the sensor typically has a baseline resistance value of 1 kilo-ohm (KΩ) or higher. These baseline values can change by as much as ± 50% from time to time. For example, certain chemical sensing resistors may have a baseline resistance that varies between 15 and 45 kilohms. This large resistance variation compels the challenge in designing the resistance measurement circuit. In addition, the ratio of the initial baseline resistance, which represents the analyte concentration, to the resistance change, Δ
R / R can be very small (ie, on the order of hundreds of millions, 0.01%). The smallness of this change also compels the challenges in designing the measurement circuit. Further, some sensor module embodiments include multiple (eg, 32) chemical sensing resistors, and it is desirable to measure the resistance of all resistors with a minimum of circuit complexity.

FIG. 12B shows an example of a voltage divider network used to measure the resistance of the chemical sensing resistor 1220. Chemical sensing register (Rch
) 1220 is a reference register (R) for configuring a voltage divider network.
ref) 1222 in series. In one embodiment, multiple networks of voltage dividers are constructed, with each network including a chemical sensing resistor serially coupled to a corresponding reference resistor, each chemical sensing resistor being one network. The reference register is selected to have a relatively low temperature dependence. In an alternative embodiment, a single reference resistor is combined with all chemical sensing resistors.

Referring back to FIG. 12A, the power supply 1224 is such that a small resistance change in each chemical sense resistor causes a detectable change in the output voltage of the network.
Supplies a predetermined reference voltage (Vref) to the voltage divider network. By appropriate selection of the reference resistance value, the current through each chemical sensing resistor can be limited to, for example, about 25 microamps (μA) or less. This small current reduces the amount of 1 / f noise and improves performance.

The analog voltage from the resistive divider network is transferred to the multiplexer (MUX
) 1226 to an analog-to-digital converter (ADC) 1230. The MUX 1226 in turn selects the chemical sensing registers on the sensor module. Optionally, a low noise amplifier 1228 can be used to amplify the voltage prior to digitization in order to improve the ADC's capability and provide increased resolution.

In one embodiment, ADC 1230 is a 22-bit (or higher) delta-sigma ADC with wide dynamic range. This is a low noise amplifier 12
Allows 28 to be set to a fixed input (ie use of a single precision register). Commercially available low cost delta-sigma ADCs can reach sampling rates as fast as approximately 1 millisecond per channel.

In one embodiment, the reference voltage provided by the power supply 1224 to the voltage divider network is also provided to the reference input of the ADC 1230. Internal ADC123
0 compares the divider network output voltage with this reference voltage to produce a digitized sample. With this scheme, the detrimental effects of the divider network output voltage due to reference voltage variations are substantially reduced.

The digitized sample from ADC 1230 is provided to processor 1210 for subsequent processing. The processor 1210 also sends the timing signals to the MU.
Supply to X1226 and ADC1230. Timing for data collection can also be provided to the ADC via the serial link via the select line of the MUX.

FIG. 12C is a diagram of another embodiment of the electrical circuit within the e-nose device 100. Figure 1
In 2C, four 8-channel multiplexers (MUXes) 1256a-12
56d is provided for greater flexibility. The inputs of MUXes1256 are coupled to a voltage divider network (not shown), and MUXes1256
The outputs of a-1256b are coupled to four amplifiers 1258a-1258d, respectively. The select lines of MUXes 1256 are processor controlled. External MUXe
The use of s provides low on-resistance and fast switching time. Amplifier 1
The output of 258 couples to the four inputs of ADC 1260.

Each amplifier 1258 includes a digital-to-analog converter (DAC) 126.
A differential amplifier having a reference (ie, inverting) input coupled to 2. The amplifier DC offset is measured by measuring the offset of the ADC 1260 and operating the DAC 1262 to provide the appropriate offset correction voltage.
Controlled by 0. The offset can be adjusted prior to the actual measurement in order to suppress DC drift (ie, baseline resistance drift of the chemical sensing resistor). Further electrical stability is maintained by placing the ADC 1260 onboard and using a differential MUX.

In the embodiment of FIGS. 12A and 12C, amplification is performed in the voltage divider network to perform PPM change detection of resistance. It can be shown that a gain of 50 provides detection of a 1 PPM increase. In FIG. 12C, amplifier 1258 also fits the signal sampled at the full scale input of ADC 1260. This matching is performed by removing the DC component (using DAC 1262) and amplifying the AC component. In this way, it is possible to detect single digit PPM changes even in baseline registers that change by ± 50%.

In FIGS. 12A and 12C, the ADC used to measure the resistance value can be implemented using a high resolution delta-sigma ADC (ie, 4 channels). The high resolution of the delta-sigma ADC combined with the sensor bias method described above provides high flexibility and accuracy. Currently available delta-sigma ADCs can provide an effective resolution of 20 bits or more at 10 Hz and 16 bits at 1000 Hz with low power consumption as low as 1.4 mW.

In one embodiment, the delta-sigma ADC includes differential inputs, programmable amplifiers, on-clip calibration and serial peripheral interface (SPI) compatibility. In one embodiment, the differential MUX inside the ADC is (1) arranged with respect to ground for enhanced and efficient measurement resolution, and (2) with reference voltage for accurate measurements. Are arranged. The status signal from the ADC indicates when the internal digital filter is stable and thus provides an indication to select the next analog channel for digitization.

In FIGS. 12A and 12C, processors 1210 and 1260 are designed to perform an application specific integrated circuit (ASIC), digital signal processor (DSP), controller, microprocessor or other function described herein. It can be implemented as a circuit.

One or more memory devices are provided for storing program code, data and other placement information and are mounted next to the processor. Suitable memory devices include random access memory (RAM), dynamic RAM (D
RAM), flash memory, read only memory (ROM), programmable read only memory (PROM), electrically programmable ROM (EPROM)
And electrically erasable PROM (EEPROM) and other memory technologies. The size of the memory depends on the application and can be easily expanded if necessary.

In one embodiment, the processor executes program code that coordinates various operations of the e-nose device. The program code includes interactive software that assists the user in selecting operating modes and methods and launches tests. After the e-nose device has performed a test or operation, the user is optionally presented with brief results. In embodiments where the device includes a processor and embedded algorithms, complex functionality and capabilities may be provided by the device. In another embodiment, where simplified electronics are provided, the complex functionality and capabilities of the e-nose device are optionally launched and driven from a host computer using PC-based software.

The processor can likewise be used to provide temperature control of each individual sensor array device within the sensor module. In some embodiments, each sensor array device can include a rear heater. Further, the processor can control the temperature of the sample chamber (eg, chambers 710a and 710b of FIG. 7A) by either heating or cooling with a suitable electrothermal device (not shown).

After the processor collects data representing a set of varying resistance measurements of a particular unknown test sample, the processor continues to store that data in memory (ie RAM 12).
12 or ROM 1214) associated with a set of previously collected reference value sets represented. This comparison facilitates the identification of analytes present in the sample chamber and the determination of the amount or concentration of such analytes, as well as the detection of changes in such identification and quantification over time. Various analyzes suitable for identifying analytes and quantifying concentrations include principal component analysis, Fisher linear analysis, neural networks,
Includes genetic algorithms, fuzzy logic, pattern recognition and other algorithms. After the analysis is complete, the resulting information is displayed on display 120 and / or transferred to a host computer via interface 1232.

The identification of the analyte and the determination of the sample concentration can be carried out by the "analyzer". As used herein, this analyzer may be a processor (such as processors 1210 and 1260 above) or DSP processor, a specially designed ASIC, or designed to perform the analysis functions described herein. Other circuits may be used. The analyzer may likewise be a general-purpose processor that executes the program code written to perform the necessary analysis functions.

As described above, in order to facilitate the identification of the designated analyte,
Variable data from a sensor of a particular unknown test sample (such as resistance value) can be associated with a previously collected set of reference values stored in memory. These reference values can be collected using one of at least two suitable methods, as described below.

In one method, a known standard sample is provided to the sample chamber. Known standards are
It can be supplied from a small reference cartridge (ie located in the e-nose device). The supply of this standard sample to the sample chamber can be controlled by a compact solenoid valve under the control of the processor. An advantage of using known standards is the possibility of controlling the identity of the standard. This cartridge can be replaced periodically.

Alternatively, an unknown test sample supplied to the sample chamber may be selectively “scrubbed” by its diffusion through a cleaning agent (eg charcoal). even here,
The diffusion of the test sample by the cleaning agent can be controlled by the processor via a compact solenoid valve. The advantage of this variant is that no cartridge is required. The cleaning agent is periodically cleaned, but it will be difficult to ensure that the standard sample is not contaminated.

The processors of FIGS. 12A and 12C direct data collection, perform digital signal processing and control serial peripheral devices (via SPI), I / O devices, serial communications (via SCI) and other peripherals. I do. Serial peripherals that can be controlled by the processor include ADC and DAC, 32K external E
Includes PROM (extends to 64K), 32K RAM with integrated real-time clock and battery backup, 2x8-character dot matrix display and more. Controllable I / O includes five separate temperature probes (four amplified through an amplifier and used in four independent Hester control loops with transistors), a humidity probe, two push buttons, and a green LE
Includes D and others. Serial communication to an external device uses low power RS-
Provided by the H.232 serial driver.

The processor further controls peripherals such as displays, valve assemblies and pumps. The processor also monitors the input device (eg, pushbutton switch 122 of FIG. 2A) and further interfaces (eg RS-232) located on the housing of the device (eg, electrical connector 126 of FIG. 2A).
Digital communication to the host computer via the driver).

In the example of FIG. 12C, the data acquisition is (eg, 20 bits) Delta-Sigma A.
DC, 4-channel (ie 12-bit) DAC 1262 and 4 separate 8
Includes communication and / or control with a channel high speed analog MUX 1256.

On-board memory (ie external RAM) is provided for the purpose of data logging. In one embodiment, the memory is organized into blocks of 32K x 8 bits. In one embodiment, each sample from the ADC is 24 bits and occupies 3 bytes of memory. Thus, each 32K-byte memory block has 10
, 666 provides memory for samples. If all 32 channels were used for data logging purposes, the memory block provides 333 data points / channel storage. An internal power supply stores the data stored in memory, which is designed to have a lifespan of 5 years or more. The sampling rate of the ADC is programmable and the data can be downloaded to the host computer through the RS-232 interface.

Communication between the on-board processor and the host computer can be used to deploy the device and download data via the RS-232 interface in real time or at a later time. Transfer rate of 9600 bits / sec is about 40
0 data points / second can be transferred and higher transfer rates can be used.

13A-13G depict an example of a suitable flow chart of the functional steps performed by an e-nose device implementing the measurement and analysis procedures generally outlined above. These flow charts show how the e-nose device is initialized and controlled through its various modes of operation. In one embodiment, these modes of operation include 1) a target mode in which the instrument is calibrated by exposing the instrument to a sample of known identity, 2) a qualitative analysis mode in which the instrument is exposed to an unidentified sample, and 3) excluding residual samples. The removal mode is included.

FIG. 13A shows a flow diagram of an embodiment of the main program menu of the e-nose device. Initially, the various electronic elements of the e-nose device (ie the display and various internal data registers) are initialized or reset at step 1312. The function background subroutine is then executed in step 1314. This subroutine is described in detail in FIG. 13B.

After the function background subroutine is executed, the program proceeds to step 1316, where the processor determines if pushbutton switch B1 (eg switch 122a of FIG. 2A) is pressed. If so, the program proceeds to step 1318, where the operating mode of the device advances to the next successive mode (ie, target mode to qualitative analysis mode). Then, the program returns to step 1314 to execute the function background subroutine again. The enhancement of the operating mode of the device continues until it is determined in step 1316 that switch B1 is no longer pressed.

If it is determined in step 1316 that pushbutton B1 is not (or is no longer pressed) pushbutton switch B2 (eg, FIG. 2A).
The processor proceeds to step 1316, where the program determines if switch 122b) has been pressed. If switch B2 is not pressed, the program returns to step 1314 via idle loop 1322 and executes the function background subroutine again. Alternatively, if in step 1320 it is determined that push button B2 is pressed, the program proceeds to execute the selected mode of operation. This is accomplished by the flow chart depicted in Figure 13C. FIG. 13B shows a flow diagram of an example of a function background subroutine (step 1314). Step 13
At 30, a signal representing the measurement and parameters selected by the user (ie temperature and humidity in the sample chamber of the sensor module) is positioned to detect the instrumentation of the ADC.
(Also referred to as internal ADC). The state of the push button switch (eg, switches 122a-122c in FIG. 2A) is determined in step 1332 based on the signal from the internal ADC. The signals controlling the heaters located on the various sensor array devices of the sensor module are updated in step 1334. The signals representing the measurements of the divider network, constituted by the chemical sensing registers and their corresponding reference registers, are read from the ADC device (also referred to as external ADC) in step 1336. Finally, in step 1338, the processor processes any commands received from the host computer via the serial data line. Such commands can include, for example, program information regarding the identities of various standard samples supplied to the e-nose device in the target operating mode. Thus, the function background subroutine ends.

FIG. 13C shows a flow diagram of an embodiment of a subroutine for determining which operating mode is executed. At step 1340, a determination is made whether the selected operating mode is the target mode. If not, step 1342
It is determined whether the operation mode selected in step 1 is the qualitative analysis mode. Normally, the qualitative analysis mode is selected only after the target mode subroutine has been executed for all specified target samples. If the selected operation mode is the qualitative analysis mode, in step 1344 the qualitative analysis mode subroutine (see FIG.
The program executes (see E).

Otherwise, if the selected operating mode is not the qualitative analysis mode, then a determination is made in step 1346 whether the selected operating mode is the removal mode. If so, the program executes the remove mode subroutine (depicted in FIG. 13F) at step 1348. Otherwise, the program proceeds to step 1350, Remove Target Mode Subroutine (depicted in FIG. 13G).
To execute. The removal target mode is the default mode.

Returning to step 1340, if the selected operating mode is determined to be the target mode, the program proceeds to step 1352 where a function background subroutine is executed. As described above, this provides updated values to the internal and external ADCs. Thereafter, in step 1354, it is determined whether push button switches B1 and B2 are simultaneously depressed.
If so, the program does not execute target mode and instead returns to the idle loop (step 1322 of FIG. 13A).

Otherwise, if it is determined in step 1354 that both pushbutton switches B1 and B2 have not been pressed simultaneously, the program switches to switch B1.
Proceed to step 1356, where it is determined if was pressed. If so, the program proceeds to step 1358 where the specific target number is stepped. In one embodiment, the e-nose device is arranged to measure a large number (eg, 8) of different target samples and step 1358 allows the operator to select a particular target sample to be aspirated into the device for measurement. To The identities of these target samples were previously loaded into the device from the host computer. The program then returns to step 1352 to execute the function background subroutine. Each time switch B1 is determined to have been pressed, the program cycles through this loop, stepping through the total number of preloaded target samples.

If it is determined in step 1356 that switch B1 was not pressed, the program proceeds to step 1360 which determines if switch B2 was pressed.
If not, the program returns to step 1352 which executes the function background subroutine. Otherwise, if it is determined in step 1360 that switch B2 has just been pressed, the program proceeds to step 1362 to execute the target mode subroutine (depicted in FIG. 13D).

FIG. 13D shows a flow diagram of one embodiment of the target mode subroutine.
At step 1370, the most recently updated set of measurements is retrieved from the external ADC. These measurements represent the baseline resistance of the 32 chemical sensing resistors of the sensor module. The pump is then adjusted in step 1372 to draw the designated target sample into the sample chamber of the sensor module. Then, in step 1374, a new set of measurements is retrieved from the external ADC. This new set of measurements represents the resistance values of 32 chemosensing resistors in response to a target sample drawn into the sample chamber.

At step 1376, the 32 resistance measurements (ie, “response vector”) to this particular target vapor are normalized. In one embodiment, this normalization aligns the sum of all 32 measurements to 1 × 10 6. The normalized response vector for this target sample is then stored in memory at step 1378.
Finally, in step 1380, a pump and valve assembly is placed to introduce clean air into the sample chamber. Thus, the target mode subroutine ends and the program returns to the idle loop (step 1322 in FIG. 13A).

FIG. 13E shows a flow diagram of one embodiment of the Qualitative Analysis Mode Subroutine. Steps 1390, 1392, 1394 and 1396 of FIG. 13E are similar to steps 1370, 1372, 1374 and 1376 of FIG. 13D, respectively.
The normalized response vector for the unknown sample calculated in step 1396 is normalized to the various target samples determined in step 1398 by the faster passage through the target mode subroutine (FIG. 13D) and stored in memory. Response vector. In particular, the difference between each normalized response vector is calculated in step 1398 and the vector of least difference is calculated in step 131.
00 (i.e. least mean squares analysis). Similarly, in step 13100,
The result of that decision is displayed on the display. Finally in step 13102,
The pump and valve assembly is adjusted to introduce clean air into the sample chamber. Thus, the qualitative analysis mode subroutine ends, and the program returns to the idle loop (step 1322 in FIG. 13A).

FIG. 13F shows a flow diagram of one embodiment of the remove mode subroutine. At step 13120, the pump and valve assembly is adjusted to introduce clean air into the sample chamber via the intake port. Thus the program returns to the idle loop (step 1322 of Figure 13A).

FIG. 13G shows a flow diagram of one embodiment of the remove target mode subroutine. In step 13130 all of the target sample stored in memory is erased. Thus the program returns to the idle loop (step 1322 of Figure 13A).

FIG. 14 shows a diagram of an embodiment with menu selections for an e-nose device. The main menu 1408 in FIG. 14 displays the measurement modes available for a particular e-nose device. The available modes can depend on, for example, the particular module installed within the e-nose device. In one embodiment, the following modes, qualitative analysis, quantitative analysis (Qu), process control (PC), data log (DL), training and diagnostics are available in the main menu. Upon making a menu mode selection on menu screen 1408, a menu screen 1410 appears that asks the user to select a particular method from the set of available methods.

Upon selection of the ID method option, a menu screen 1412 appears that asks the user to press “sniff” to begin the qualitative analysis or “cancel” to return to the main menu. Upon selection of the sniff option, the e-nose device initiates the qualitative analysis process shown on menu screen 1414 and provides the results shown on menu screen 1416 upon completion of the process. The user is offered the option to save the result.

Selecting the Qu method option brings up a menu screen 1420 that asks the user to select a target. If the identity of the target is unknown, menu screen 1422 provides the user with the option to perform a sniff to identify the unknown target. Upon selection of the sniff option, the e-nose device initiates the qualitative analysis process shown on menu screen 1424 and provides identity as shown on menu screen 1426 upon completion of the process. If the sample is qualitatively analyzed once, or if its identity is already known, the target can be quantitatively analyzed on the menu screen 1430,
Upon completion of the process, the results are provided as shown by menu screen 1432.

Upon selection of the PC method option, a menu screen 1440 appears that asks the user to press “sniff” to control the process or “cancel” to return to the main menu. Upon selection of the sniff option, the e-nose device initiates the process controls shown on menu screen 1442 and provides status reports as shown on menu screen 1444.

Upon selection of the DL method option, a menu screen 1450 appears that asks the user to press “sniff” to begin data logging or “cancel” to return to the main menu. Upon selection of the sniff option, the e-nose device initiates the data log shown on menu screen 1452 and provides status reports as shown on menu screen 1454.

Selecting a training option brings up a menu screen 1460 that asks the user to select one of many training methods. A menu screen 1462 appears that asks the user to select a particular method and to select one of many targets. Upon selection of the sniff option, the e-nose device begins the training process for the method and target selected by the user, as shown in menu screen 1466.

Selection of a diagnostic option causes a menu screen 1470 to appear that asks the user to select to launch diagnostics. Includes possible diagnostics of eg RS-232 port, USB port, sensor range test, memory, processor and program checksum. The user selects a particular diagnostic and a menu screen 1462 appears prompting the user to select one of many targets. Upon selection of the sniff option, the e-nose device initiates the selected diagnostic test as shown in menu screen 1472 and provides diagnostic results as shown in menu screen 1472.

Modular Design In one particular aspect of the invention, the e-nose device is designed with modular parts. For example, the nose, filter, manifold, sensor module, power pack, processor, memory, etc. can be placed in a module that can be optionally installed or replaced as needed. The modular design offers many advantages, some of which relate to the following characteristics: interchangeable, removable, replaceable, upgradeable and non-fixed.

The modular design allows the e-nose device to be designed for use in a variety of industries and for a variety of applications. For example, multiple sensor modules, filters, etc. can be added as the list of samples to be measured grows. Also, in certain embodiments, the modular design can provide improved performance. Various modules (ie, nose, filters, manifolds, sensor modules, etc.) can be designed to provide accurate measurements for a particular set of test samples. Different modules can be used for measuring different samples. Therefore, performance is not sacrificed by the use of a small portable e-nose device. For example, to detect high molecular weight analytes, plug in a special nose tip. Another nose tip can then be plugged in to detect low molecular weight analytes.

The modular design can also result in an economical e-nose design. Since some of the components can be easily replaced, it is not necessary to dispose of the entire e-nose device if one particular component becomes worn. Only failed components are replaced. Also, in certain embodiments, the modular design can provide an upgradeable design. For example, the processor and memory modules (individually or in combination) may be located in an electronic unit that may be upgraded by new technology or as needed for a particular application. Additional data may be provided by simply swapping memory modules to store more data. Also, an analysis algorithm can be included in the program module inserted into the e-nose device. The program modules can then be swapped as desired. Also, the modular design can include disposable modules. This can be advantageous, for example, when analyzing toxic samples.

Nose In the above embodiment, the e-nose device has a sampling rod (or nose or snout) on the outside. The nose can be attached to the device using mechanical interlocking features such as simple quarter turn, screws, snap mechanical arrays, and other interconnections. Many materials, such as injection moldable materials, can be used to manufacture the nose component. In one particular embodiment, the noses are interchangeable and use standard luer interconnections. For example, the nose has a length of about 1 inch to about 50 inches (about 2 inches).
． 5 cm to about 127 cm), preferably about 6 inches to about 20 inches (about 15 cm to about 51 cm) in length. The nose may optionally be ridged or a long flexible hose or flexible snorkel. In some embodiments, the nose has a luer needle at the olfactory end. Optionally the nose withstands the internal pressure and is joined to the pressure valve.

As shown in FIG. 3B, the nose can be provided with various sizes and shapes.
For example, the nose 130d has a wide opening which is advantageous when sampling gas, for example. In contrast, the nose 130f has a sharp tip that is more suitable for sampling at a specific site. In some alternative embodiments, an intake port (
Intake port 132, etc.) can be used. The intake port can replace or be added to the outer nose.

Sensor Modules In certain aspects, chemical sensitive sensors within the sensor module can be made to be particularly sensitive to a particular type of vapor. For example, one array of such modules can incorporate suitable vapor sensors to identify polar analytes such as water, alcohols, and ketones. Examples of suitable polar polymers for use in such vapor sensors include poly (4-vinylphenol) and poly (4-vinylpyrrolidone).

The identification of the sensor module can optionally be carried out by means of an identification register (not shown) with a selective resistance. Therefore, the processor measures the resistance of the identification register prior to processing the undefined resistance measurements collected in the chemical sensitive register of each such sensor module. In this way, the nature of the module's chemically sensitive resistors can be ascertained first. The analyte detection mechanism is disclosed in the aforementioned International Patent Application No. WO99 / 08105.

Display In some embodiments, the display is a liquid crystal display (LCD).
In another embodiment, the display is a graphical LCD that allows the device to display textual information and graphics. This type of display provides a high quality product interaction process. An example of an LCD module is a screen size 57.56 mm x 35.99 mm, resolution 3 with 0.8 dot pitch.
Some are from Epson, such as the EPSON EG7502 (TCM AO822), which has a 20 × 200, and LED edge backlight that refracts and traverses the screen. Various other LCD modules are also suitable. Preferred LCD modules exhibit one or more of the following features. That is, a higher resolution (320 ×) that is smaller than (1) but allows a comfortable viewing area.
200 and fine dot pitch), (2) low power consumption (eg 3 mW to 9 mW), (3) multi-line scanning (active address) technology,
Features include (4) integrated "touch panel", (5) integrated power and controller chip, (6) LED backlight for smaller modules, (7) display that can be shared with video.

Input Devices In certain embodiments, the e-nose device optionally includes input devices such as push buttons, keypads, keyboards, touch screens, switches, other input mechanisms, or combinations of the above. The keypad can be made of various materials. In one particular embodiment, the keypad is molded from silicone rubber and advantageously provides a gloved hand with a responsive feel. Additionally, operational controls can optionally be incorporated into the keypad and buttons. For example, an "smell inhalation" button can optionally be positioned in the keypad.

The keypad may optionally be a thin film keypad. To implement this, the keypad is formed from a laminated sheet of acrylic resin, mylar, PC, or other suitable material. The odor inhalation dome can be used to make the user feel more responsive. Native graphics can be built into the keyboard. The keypad is preferably flexible with graphics, easy to clean and waterproof. In addition to this, the keypad is configured to have a small stroke distance. In another example, a microswitch is used for a "smell inhalation" button or the like to further enhance the feeling of "click" response and generate a low level audible signal.

In a particular embodiment, the e-nose device optionally comprises a pointer. Pointers are advantageous because they allow a wider range of applications and are easier to use in the field. In one particular aspect, pointers can be used to read barcodes to facilitate inventory management. Further, the device optionally comprises a pad. Pads address a range of applications such as field, practice, or research. The e-nose device optionally comprises other input devices such as a touch screen.
Suitable touch screens are analog resistive. Other touch screens include those similar to touch screens on PDAs, GPS and other products. Still other touch screens are those of the electromagnetic resonance type, which have a dedicated stylus, such as an optional battery-less stylus. Additionally, touch screens include, but are not limited to, electrostatic, GSAW, and analog resistive and capacitive. Analog resistive touch screens are preferred because high and low resolutions are easily obtained.

In one particular embodiment, the e-nose device informs the user by providing general and specific information about the current mode of the device. The operator of the device can know what options are available. Guidelines and handbooks can be used to help users interact with their product. In some instances, the explanations and instructions are concise, concrete and clear. Graphics and icons help the user through interaction with their artifact. The user is instructed to shut down the device when necessary and return to the appropriate previous screen. Together, these various features provide a quick, easy, and reliable device interaction.

In another embodiment, the e-nose device provides the user with information regarding the status of the device. Examples include, but are not limited to, action start, operation execution, and input wait. In addition, I / O parameters of other devices such as hardware control,
That is, (1) scroll up-keypad, (2) scroll down-keypad, (3) select-keypad, (4) cancel-keypad, (5).
Smell suction-keypad, (6) power on and backlight on / off, (7) digital input-connector, (8) analog output-connector, (9) serial out (R
S232) -RJ11, (10) USB-standard A, (11) display contrast- (finger ring, analog pot), (12) system reset-pinhole, (13) battery recharge-jack, (14) air port. , (15) nose suction port (sample odor suction port), (16) discharge (discharge) port, and (17)
There is, but is not limited to, a reference intake.

Power Pack eNose device optionally includes a power pack such as a battery for power supply. In one particular embodiment, the device operates with a DC supply voltage of about 3.3 volts and about 5.0 volts. In one specific embodiment, the device consumes less than about 3.2 watts and the typical average power consumption is 1.8 watts. In one embodiment, the device can operate for about 1 hour to about 20 hours without the need to recharge the power pack.

The power pack includes nickel-cadmium (NiCd), nickel-metal hydride (
NiMH), lithium-ion (Li-ion), sealed lead-acid (SLA),
Alternatively, it can be manufactured using other battery technologies. Preferably, the power pack is lightweight and has a high power density to reduce battery volume. Lithium-ion batteries exhibit a relatively high internal resistance and a wider range of voltages during discharge compared to other battery chemistries. A voltage regulator can be used to provide the proper voltage to the circuitry within the e-nose device. A switching regulator may be used instead of a linear regulator for efficiency. The voltage regulator can also be used to provide multiple output voltages to other circuit elements within the e-nose device. In one particular example, the output voltage required of the power supply includes values above and below the battery voltage. In these examples, SEPICs for switching voltage regulators
Topology can optionally be used. The conversion efficiency of such a switching type voltage regulator is about 85%. To supply a load with about 18 watt-hours of energy using such a switching regulator, the lithium-ion battery pack requires about 21 watt-hours of energy.

In one specific embodiment, optionally a volume of about 100 cubic centimeters (
cc), a lithium-ion (Li-ion) battery pack weighing approximately 250 grams can be used in an e-nose device. In another specific embodiment, the weight is about 37.
A nickel-metal hydride (NiMH) battery pack having 0 grams and a volume of about 150 cc can be used. Other batteries that can deliver an equivalent amount of energy have about 750 grams and 350 cc of nickel-cadmium (NiCd).
) There is a battery pack, but it is not limited to this.

Generally, as the number of times of charging increases, usable battery capacity becomes low temperature (eg, 0 to 10 ° C.)
And lower for higher temperatures (eg 40 to 50 ° C.). In addition, for accurate “gas metering” under such conditions, the Smart Battery System
(SBS) can also be used. SBS is a commercially available system, Syst
It is a part of em Management Bus (SMB). SBS allows battery packs to interact with automatic chargers and other system intelligence using physical protocols similar to Philips' I2C bus protocol. The SMB software protocol allows direct interaction with parameters such as state of charge, battery pack voltage, battery temperature, number of discharge cycles, etc. Currently, several suppliers of integrated circuits propose single-chip implementations of SMB interfaces. Alternatively, the Microchip Technology
A custom-programmed microminiature controller such as the Ogy PIC chip can be used for this purpose.

In some embodiments, the device comprises an optionally rechargeable power pack. In some alternative embodiments, the device optionally comprises a battery, such as four AA batteries. Battery chemistries vary. The device optionally supports alkali compatibility. The device optionally has a rechargeable pack fitting for a secondary battery of the same or smaller size as the power pack.

Implementation of a Specific Electronic Nose Device An e-nose device can be implemented in various components due to its various features and used in various applications. Some specific implementations are provided below.

In one specific implementation, an e-nose device comprises a sensor array of 32 sensors, which are composed of electrically conductive particles uniformly dispersed within a polymer matrix. Each polymer swells like a sponge when exposed to a test medium (eg, vapor, liquid, gas), thereby increasing the resistance of the composite. Polymers vary in degree of swelling due to their unique response to different analytes. This resistance change is different throughout the sensor array, resulting in a characteristic trailing response. Whether the analyte corresponds to a complex mixture of chemicals in the test sample or is a single chemical, the e-nose device provides a distinct electrical "fingerprint" of the sample of interest. Provide enough polymer array to yield. The pattern of resistance change of the sensor array indicates the identity of the analyte, while the width of the pattern indicates the concentration of the analyte. The normalized resistance change is then transmitted to a processor that identifies vapor type, quantity, and quality based on the detected pattern in the sensor array.

In another specific implementation, a portable e-nose device for use in the field of detecting volatile compounds is made according to the present invention. The device incorporates an easily readable graphic LCD with a backlight, and one or more light emitting diodes (LEDs) to indicate the mode of operation. The interaction port is provided to allow the data to be easily downloaded into the spreadsheet package. A fast response time combined with a simple one-button operation results in a valid and accurate measurement of the sample. Power is supplied by replaceable or rechargeable batteries. The portable e-nose device, which is housed in a sturdy, water resistant case, is suitable for a variety of environments.

In yet another specific implementation, the e-nose device is designed to capture and store data retrieved from 32 independent sensor elements. e-nose device includes inlet / outlet port, pump, 3-way solenoid switch, LCD, push button,
3 with LED, humidity probe, temperature probe, and digital interface
It is equipped with a 2-channel sample chamber.

The power supply is designed to accept 9V DC. Rectifying diodes are added to protect the circuit. Two onboard 5 volt linear voltage regulators are used for analog and digital circuitry, respectively. A precision-embedded Zener diode is provided to provide a +2.5 volt reference. The overall design is a combination of 3V and 5V to reduce the power consumption of the handheld device.

The sample chamber contains 32 sensor elements mounted on 4 ceramic supports, each with 8 sensor elements. The support is manufactured using a co-fired ceramic (alumina) process with composite microelectronics. The electrodes and terminals are deposited as a thick film using screen printing techniques. A resistance path is provided (for example, 3 paths),
It can be used as a heating element. Directly mounted thermistors can be placed on the backside of the support to form a heating / cooling control loop.

An inlet port is provided and a baffle can be inserted to fan out the incoming sample flow. The outlet port is associated with the ambient pressure. The sample chamber is made of Teflon ™, is airtight, and is attached to the PCB. The on-board pump can force the sample flow into the sample chamber at a pressure slightly higher than 14.7 psi (about 10 MPa). An on-board three-way solenoid switch provides processor-controlled switching between a known source of reference material (ie, for “zeroing” or recalibration as needed) and an unknown test sample. Can be done. 4 ceramic supports, 2 sets of 20 pins, 50 mil (about 1.3 mm)
Spaced, inserted in two rows of connectors. The spacing between rows is 100 mil (about 2.5
mm). The temperature probe is inserted into one connector and the humidity probe is inserted into the other connector. Temperature and humidity probes are used for diagnostics.

A biasing network can be implemented that biases the chemically sensitive resistors in DC mode operation. The network is a ratio metered network that is easy to implement, stable, and has a wide dynamic range. It has been shown that a chemically sensitive change in electrical resistance of 50 PPM can be measured.
Further, as shown in Table 1, baseline changes above ± 50% can be explained by the minimal changes in applied power.

[0126]

[Table 1]

Assuming Johnson noise is the dominant noise source, it is possible to calculate an average noise voltage of 0.3 μV over a bandwidth of 10 Hz and thus detect these step changes. . Low current (ie <25μA)
Maintaining reduces 1 / f noise. Generally, the bias method is a constant voltage DC system. The current is limited to the order of microamps (μA) per sensor element and the applied power is the order of microwatts (μW). The current is limited to increase flexibility and the output voltage is regulated by a resistor.

A series of four cognate ester analytes were detected using the handheld sensing device of the present invention. The analytes detected were ethyl esters of propionic acid, butyric acid, valeric acid, and hexanoic acid. The response data was then analyzed using principal component analysis. Principal component analysis (PCA) is a powerful visualization tool that provides a way to measure the dimensionality of data. PCA finds a linear combination of the original independent variables that accounts for the largest amount of variation and provides the best expected view of variability within independent variable length blocks. Natural clustering within the data is easily determined.

FIG. 15 shows a graph of principal component analysis of the response to a series of esters using the handheld sensing device of the present invention. As shown in FIG. 15, the ester analytes were clearly identified by the handheld device of the present invention.

Application of Analytes and e-Nose Devices The analytes that can be detected by the e-nose device of the present invention include alkanes, alkenes, alkynes, dienes, alicyclic hydrocarbons, arenes, alcohols. ,
Ethers, ketones, aldehydes, carbonyls, carbanions, heterocycles, polynuclear aromatics, organic derivatives, biomolecules, microorganisms, bacteria, viruses, sugars, nucleic acids, isoprene, There are, but not limited to, isoprenoids, and fatty acids and their derivatives. Many biomolecules such as amino acids are suitable for detection using the sensor array of the present invention.

The e-nose device can be used to diagnose ill hosts including infection and metabolic problems.
It can be used to allow medical and dental care service providers to quickly and accurately identify chemical constituents in breaths, wounds, and body fluids. For example, the e-nose device can be used to test skin condition for anesthetic administration or to determine the duration of ovulation in fertility therapy. Alternatively, the handheld device can classify and identify microorganisms such as bacteria.

The e-nose device can be used to position the olfactory sense to identify complex systems or states of matter and provide versatility and reliability not found in conventional environmental or chemical monitoring devices. be able to. Advantageously, this device should be used to measure the chemical environment distribution in the presence of hazardous materials and to assist paramedics in the precise selection of fire protection agents, containment strategies, and protective equipment. it can. The e-nose device can be used to detect leaks in pipelines and storage containers.

The e-nose device can be used for food quality and process control. For example,
The device can be used for sampling intermediate results, or for continuous monitoring of lot-to-lot homogeneity and spoilage at various stages of the product, including production (ie cultivation), arrangement and delivery. The device can also be used for disposable packaging by providing objectivity not found in conventional rotting, freshness, and contamination monitoring techniques. The e-nose device can also be used to protect elderly people, who tend to lose their sense of smell over time. This device can be used to reduce the risk of food poisoning or the intake of damaged food and can be integrated with household appliances such as refrigerators and microwave ovens.

The e-nose device can be used in a wide variety of industrial applications including, but not limited to: Namely, commercial power, oil / gas petrochemistry, chemistry / plastics, automatic ventilation control (cooking, smoking, etc.), heavy industry, environmental toxicology and treatment, biomedical, cosmetics / fragrances, drugs, transportation, emergency response , And law enforcement ・ Combustible gas, natural gas, H ₂ S, atmosphere, control of exhaust, intake air, smoking, harmful spills, harmful effluents, escaped exhausts, and harmful spills. Detection, identification and / or monitoring of things, freshness detection, control of fruit ripeness, fermentation processes, and monitoring and control of beverages, foods and produce such as flavor composition and identification, illegal substances, Explosives, neglect of transformants, refrigerants and fumes, formaldehyde, diesel / gasoline / aircraft fuels, hospital / medical anesthesia and sterilization gases, remote surgery, fluid analysis, drug discovery, Infectious disease detection and breathing applications, worker protection, arson interrogation, identification, ambient monitoring, aroma blending, and-solvent recovery effectiveness, refueling operations, shipping container inspection, enclosure Space survey, product quality test, material quality control, product confirmation and quality test.

Not only is the present invention sufficiently small and lightweight to be handheld, but also modular and conveniently adapted to be used to detect the presence and identity of a wide variety of specified vapors. It will be appreciated from the above description that there is provided an improved vapor sensing instrument capable. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that various modifications can be made without departing from the invention. Therefore, the invention is defined only by the claims.

[Brief description of drawings]

[Figure 1]   FIG. 6 is a pictorial diagram of an operator using the e-nose device of the present invention.

[FIG. 2A]   FIG. 7 is a top perspective view of an example of an e-nose device.

FIG. 2B   FIG. 7 is a bottom perspective view of an example of an e-nose device.

FIG. 3A   6A-6C are six perspective views of another e-nose device embodiment.

FIG. 3B   FIG. 3B illustrates four different embodiments of the e-nose device of FIG. 3A.

[Figure 4]   FIG. 6 is a diagrammatic view of an example of a subsystem of an e-nose device.

[Figure 5]   2B is an exploded perspective view of some of the major components of the e-nose device of FIG. 2A. FIG.

FIG. 6A   FIG. 9 is an exploded perspective view of an example of a mechanical subsystem of an e-nose device.

FIG. 6B   FIG. 9 is an exploded perspective view of an example of a mechanical subsystem of an e-nose device.

FIG. 6C   It is an exploded perspective view of an example of a filter.

FIG. 7A is a perspective view of an embodiment of a sensor module including four sensor devices mounted in two sample chambers.

FIG. 7B is a top cross-sectional view of an embodiment of a sensor module including four sensor devices mounted in two sample chambers.

FIG. 7C   It is a perspective view of a sensor array device.

FIG. 8A is a perspective view of another sensor module embodiment that includes four plug-in sensor devices in a single sample chamber.

FIG. 8B is a top cross-sectional view of another sensor module embodiment that includes four plug-in sensor devices in a single sample chamber.

FIG. 9A is a perspective view of yet another sensor module embodiment including a single sensor array device.

FIG. 9B is a side cross-sectional view of yet another sensor module embodiment including a single sensor array device.

FIG. 9C is a top partial cross-sectional view of yet another sensor module embodiment including a single sensor array device.

[Figure 10]   FIG. 8 shows various accessories for an e-nose device.

FIG. 11 is a perspective view of an e-nose device shown mounted vertically on a charging station and connected to a host computer.

FIG. 12A   It is a diagram showing an example of an electric circuit in an e-nose device.

FIG. 12B shows an example of a voltage divider network used to measure the resistance of a chemical sensing resistor.

FIG. 12C   It is a figure which shows the other Example of the electric circuit in an e-nose apparatus.

FIG. 13A illustrates an example of a suitable flow chart of functional steps performed by an e-nose device that implements a measurement and analysis procedure.

FIG. 13B illustrates an example of a suitable flow chart of functional steps performed by an e-nose device that implements measurement and analysis procedures.

FIG. 13C illustrates an example of a suitable flow chart of functional steps performed by an e-nose device implementing measurement and analysis procedures.

FIG. 13D illustrates an example of a suitable flow chart of functional steps performed by an e-nose device implementing measurement and analysis procedures.

FIG. 13E illustrates an example of a suitable flow chart of functional steps performed by an e-nose device implementing measurement and analysis procedures.

FIG. 13F illustrates an example of a suitable flow chart of functional steps performed by an e-nose device implementing measurement and analysis procedures.

FIG. 13G illustrates an example of a suitable flow chart of functional steps performed by an e-nose device that implements measurement and analysis procedures.

FIG. 14A   FIG. 7 is a diagrammatic view of an example of menu selection for an e-nose device.

FIG. 14B   FIG. 7 is a diagrammatic view of an example of menu selection for an e-nose device.

FIG. 14C   FIG. 7 is a diagrammatic view of an example of menu selection for an e-nose device.

FIG. 15 is a principal component analysis graph of the response to a series of esters using the handheld device of the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 29/18 G01N 31/00 Z 5C085 31/00 G08B 17/10 5G057 G06F 19/00 H01H 47/32 G08B 17/10 G01N 27/30 301Z H01H 47/32 G06F 15/42 (31) Priority claim number 09 / 178,443 (32) Priority date October 23, 1998 (October 23, 1998) (33) Priority claiming country United States (US) (31) Priority claiming number 09 / 271,873 (32) Priority date March 18, 1999 (March 18, 1999) (33) Priority claiming country United States (US) (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ , C , CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC , LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZA, ZW (72) Inventor Steintal, M. Gregory USA, California 90068, Los Angeles, Alciana Drive 2237 (72) Inventor Behr, Christopher K. United States, California 91775, San Gabriel, Alabama Street 419 (72) Inventor Nakayama, Robert K. United States, California 90035, Los Angeles, South Sherborne Drive 1034 # 7 F term (reference) 2G042 AA01 BA00 BA01 BA08 BB00 BB01 BB14 BD04 BD05 BD06 BD08 BD09 BD10 BD11 CA00 CA01 CA02 CB01 CB03 CB06 2G046 AA01 AA04 AA18 A31 A34 A34 A34 AA24 DC14 DC16 DC17 DD01 FA01 FB02 FE39 2G047 AA01 AA05 2G060 AB01 AB02 AB15 AB21 AB22 AB26 AC02 AD01 AD05 AD06 AE17 AE19 AE20 AF02 AF07 HB06 HC13 HC18 HC19 HE02 4G057 AB11 AB07 AB11 AB08 AB11 AB0 AB11 AB08 AB0 AB11 AB08 AB0 AB11 AB08 AC08 AB10 AB08 AB08 AB08 AB08 AB08 RR04

Claims (36)

[Claims] 1. A sample chamber defined by a housing, a sensor module mounted to the housing and including at least two sensors responsive to a test sample, and a sample chamber defined by one or both of the housing and the sensor module. A chamber having an inlet port and an outlet port incorporated therein and a sample chamber in which the at least two sensors are disposed adjacent to or in the sample chamber, and a response which is mounted on the housing and which is transmitted from the at least two sensors. An analyzer configured to analyze, the analyzer identifying, classifying or quantifying an analyte in a test sample based on responses from said at least two sensors;
Handheld sensing device equipped with. 2. The handheld sensing device of claim 1, further comprising a pump mounted to the housing and configured to pass the test sample from the inlet port to the outlet port through the sample chamber. 3. The handheld sensing device of claim 1, wherein the response from the at least two sensors comprises a set of signals indicative of changes in resistance of the at least two sensors due to exposure to the test sample. 4. The handheld sensing device of claim 1, further comprising a measuring circuit mounted on the housing and configured to detect responses from at least two sensors and output a signal corresponding to the responses. . 5. The handheld sensing device of claim 4, wherein the measurement circuit comprises a sigma-delta converter. 6. The handheld sensing device of claim 1, wherein the analyzer receives responses from at least two sensors to generate corresponding sample signatures. 7. The method comprises collecting a plurality of reference signatures for a plurality of reference samples and generating a sample signature for a test sample, wherein the analyzer is configured to compare the sample signature with the plurality of reference signatures to identify the test sample. Item 7. The handheld sensing device according to item 6. 8. The handheld sensing device of claim 1, further comprising a valve mounted on the housing and configured to pass a reference or test sample through the sample chamber. 9. The handheld sensing device of claim 8, wherein the reference sample is preconditioned. 10. The handheld sensing device according to claim 8, wherein the reference sample is selected from a plurality of reference samples. 11. The handheld sensing device of claim 1, wherein the sample chamber is sealed from the external environment except the inlet port and the outlet port. 12. The handheld sensing device of claim 1, further comprising a preconcentrator. 13. The handheld sensing device of claim 1, further comprising a thermal control circuit that controls the temperature of at least two sensors. 14. The handheld sensing device of claim 1, further comprising a sampling rod connected to the housing. 15. At least one of the sensors of the sensor module is a conductive / non-conductive area sensor, SAW sensor, quartz microbalance sensor, conductive composite sensor, chemiresistor, metal oxide gas sensor, organic gas sensor, MOSFET, piezoelectric device, infrared sensor. A member selected from the group consisting of a sintered metal oxide sensor, a Pd gate MOSFET, a metal FET structure, an electrochemical cell, a conductive polymer sensor, a catalytic gas sensor, an organic semiconductor gas sensor, a solid electrolytic gas sensor, and a piezoelectric quartz crystal sensor. Item 2. The handheld sensing device according to Item 1. 16. The handheld sensing device of claim 15, wherein at least one of the sensors of the sensor module is a conductive / non-conductive area sensor. 17. The handheld sensing device of claim 15, wherein at least one of the sensors of the sensor module is a SAW sensor. 18. The handheld sensing device of claim 1, wherein the sensor module includes a plurality of sensor array devices, each sensor array device including an array of sensors. 19. A sample chamber defined by a housing, a sensor module mounted to the housing and including at least two sensors responsive to a test sample, and a sample chamber defined by one or both of the housing and the sensor module. A chamber having an inlet port and an outlet port incorporated therein and a sample chamber in which the at least two sensors are disposed adjacent to or in the sample chamber, and a response which is mounted on the housing and which is transmitted from the at least two sensors. An analyzer configured to analyze, the analyzer identifying, classifying or quantifying an analyte in a test sample based on responses from said at least two sensors;
Use of a hand-held sensing device equipped with an instrument for detecting an analyte in a test sample. 20. A housing including a socket, a sensor module removably attached to the socket of the housing, the sensor module including at least one sensor for providing a response to a test sample; A sample chamber defined within the module, the sample chamber incorporating an inlet and an outlet port, wherein the at least one sensor is located in or adjacent to the sample chamber and mounted in the housing. An analyzer configured to analyze a response from at least one sensor, the analyzer identifying or quantifying an analyte in a test sample based on the response from the at least one sensor; A handheld sensing device further comprising: 21. Further comprising at least one additional sensor module, each sensor module being removably attached to a respective socket, at least one
21. The handheld sensing device of claim 20, configured to incorporate a number of sensors, each sensor module configured to provide a respective set of responses to a different set of samples. 22. The removably attached sensor modules each include an identifier for identifying the sensor module, and the analyzer is configured to determine the identifier included in the sensor module received in the socket. Handheld sensing device according to. 23. A sensor module configured for use with a sensing device disposed within a housing defining a socket, the sensor module comprising: a casing sized and configured to be received by the socket of the sensing device; and a sample chamber. An inlet port configured to releasably engage the first port connection of the sensing device when the sensor module is received in the socket, the inlet port receiving a test sample from the sensing device To the sample chamber, an outlet port configured to release the test sample from the sample chamber, and one or more analytes in the test sample located in or adjacent to the sample chamber At least one sensor configured to emit a response when exposed to a An electrical connector configured to releasably engage a mating electrical connector of the sensing device, the electrical connector transmitting a signal from the at least one sensor to the sensing device; The equipped sensor module. 24. The outlet port is configured to releasably engage the second port connection of the sensing device when the sensor module is received in the socket of the sensing device, the outlet port from the sample chamber. 24. The sensor module of claim 23, which emits a test sample to a sensing device. 25. The sensor module according to claim 24, wherein the casing incorporates a rear wall supporting an inlet port, an outlet port, and an electrical connector. 26. The substrate according to claim 23, further comprising a substrate for mounting the plurality of sensors.
The sensor module described in 1. 27. The sensor module according to claim 23, wherein the at least one sensor is uniformly arranged in the sample chamber. 28. Each of said at least one sensor is embodied by a chemical sensing resistor having a resistance that varies in a unique manner when exposed to one or more specified analytes in a test sample. 24. The sensor module of claim 23, wherein the sensing device includes an analyzer that detects a set of resistances of the at least one sensor and identifies a test sample based on the detected set of resistances. 29. A sensor module configured for use with a sensing device disposed within a housing defining a socket, the sensor module comprising a casing sized and configured to be received in the socket of the sensing device; and a sample chamber. An inlet port configured to releasably engage the first port connection of the sensing device when the sensor module is received in the socket, the inlet port receiving a test sample from the sensing device To the sample chamber, an outlet port configured to release the test sample from the sample chamber, and one or more analytes in the test sample located in or adjacent to the sample chamber At least one sensor configured to emit a response when exposed to a An electrical connector configured to releasably engage a mating electrical connector of the sensing device, the electrical connector transmitting a signal from the at least one sensor to the sensing device; Use of the equipped sensor module. 30. A handheld sensing device for measuring the concentration of one or more analytes in a sample chamber, wherein at least two chemical sensing resistors, each chemical sensing resistor being one in the sample chamber. A chemical sensing resistor having a resistance that changes according to the concentration of the analyte, and a regulation circuit connected to the at least two chemical sensing resistors, the regulation circuit comprising at least two chemical sensing resistors. An adjusting circuit for generating an analog signal indicating each resistance, and an analog-digital converter (ADC) connected to the adjusting circuit,
The ADC is an ADC that emits a digital signal in response to an analog signal, and an analyzer connected to the ADC. A hand-held sensing device comprising an analyzer for determining. 31. The regulation circuit of claim 30, wherein the regulation circuit comprises a set of voltage divider networks, one network for each of the at least two chemically sensitive resistors, each network providing an analog voltage. Handheld sensing device. 32. The at least one multiplexer coupled to a set of voltage divider networks, the multiplexer further comprising a multiplexer coupling an analog voltage from the set of voltage divider networks to an ADC. Handheld sensing device as described. 33. The handheld sensing device of claim 32, wherein there is at least one amplifier, each amplifier further comprising an amplifier coupled between the one multiplexer and the ADC. 34. A handheld vapor sensing device comprising a handheld housing and a sensor module mounted in the housing and incorporating a plug-in array of vapor sensors, wherein each vapor sensor has one or more different electrical responses. A sensor module that provides different vapors of the sensor module, and one or both of the housing and the sensor module define a sample chamber to which the array of vapor sensor of the sensor module is exposed, the sample chamber including a vapor inlet and a vapor outlet. A hand-held vapor sensing device is further mounted in the housing and configured to direct the vapor sample through the sample chamber from the vapor inlet to the vapor outlet, and the vapor sensor of the sensor module mounted in the housing. Configured to monitor the electrical response of the array of A monitoring device configured to generate a sensor signal for the sensor, and an analyzer mounted on the housing and configured to analyze the plurality of sensor signals to identify a vapor sample that has passed through the sample chamber by a pump. Handheld vapor sensing device. 35. In a plug-in sensor module configured for use with a hand-held vapor sensing device of the type including a hand-held housing defining a socket, the plug-in sensor module being received in the socket of the hand-held vapor sensing device. A size and configuration of the casing, the sample chamber, and the plug-in sensor module releasably engageable with the first vapor connection of the handheld vapor sensing device when received in the socket of the handheld vapor sensing device. A vapor inlet configured to receive the vapor sample from the vapor sensing device and direct the vapor sample to the sample chamber; a vapor outlet configured to discharge the vapor sample from the vapor chamber; and disposed in or adjacent to the sample chamber, A plurality of vapor sensors configured to generate different electrical signals in response to one or more vapors in the sample chamber; An electrical connector configured to releasably engage a mating electrical connector of a handheld vapor sensing device when the lug-in sensor module is received in the socket and which transmits signals from the plurality of sensors to the vapor sensing device. And a plug-in sensor module including. 36. A vapor sensing device for measuring the concentration of one or more predetermined vapors in a sample space, the chemical sensing having a resistance that varies depending on the concentration of the one or more vapors in the sample space. A resistor and a reference resistor connected in series with the chemical sensing resistor between the reference voltage source and ground such that an analog output signal is established at the node between the reference resistor and the chemical sensing resistor. To generate a digital output signal indicative of the resistance of the chemical sensing resistor in response to both the analog output signal and the voltage level of the reference voltage source, and the sample in response to the digital output signal. A vapor sensing device comprising: an analyzer for determining the concentration of one or more predetermined vapors in a space.